Scaling Supercapacitive Swing Adsorption of CO₂ Using Bipolar Electrode Stacks

Supercapacitive swing adsorption (SSA) modules with bipolar stacks having 2, 4, 8, and 12 electrode pairs made from BPL 4 × 6 activated carbon are constructed and tested for carbon dioxide capture applications. Tests are performed with simulated flue gas (15%CO₂ /85%N₂) at 2, 4, 8, and 12 V, respectively. Reversible adsorption with sorption capacities (≈58 mmol kg^-1) and adsorption rates (≈38 µmol kg^-1 s^-1) are measured for all stacks. The productivity scales with the number of cells in the module, and increases from 70 to 390 mmol h^-1 m^-2. The energy efficiency and energy consumption improve with increasing number of bipolar electrodes from 67% to 84%, and 142 to 60 kJ mol^-1, respectively. Overall, the results show that SSA modules with bipolar electrodes can be scaled without reducing the adsorptive performance, and with improvement of energetic performance.